In many traffic situations it is desired to acquire an enhanced braking effect, for example at possible collision situations and when the road grip is lost, by means of an auxiliary braking arrangement. One example of such an auxiliary braking arrangement is described in EP 2311695, where a braking mat is pressed against the road by at least one airbag in a chamber
Another example is disclosed in U.S. Pat. No. 8,356,685, where a braking plate may be lowered. When lowered, it is pressed against the road due to a lowered pressure in a vacuum chamber in the braking plate.
It is however important to reach a correct decision regarding if and when to activate such an auxiliary braking arrangement, since it is not reversible, affects the traffic situation and subjects the persons in the vehicle to increased forces due to the increased deceleration. In EP 2311695, it is for example mentioned that it is detected whether the ABS (Anti-lock Braking System) is activated or not.